The Global Modeling and Assimilation Office (GMAO) has recently released a new version of the Goddard Earth Observing System (GEOS) Subseasonal to Seasonal prediction (S2S) system, GEOS‐S2S‐2, that ...represents a substantial improvement in performance and infrastructure over the previous system. The system is described here in detail, and results are presented from forecasts, climate equillibrium simulations, and data assimilation experiments. The climate or equillibrium state of the atmosphere and ocean showed a substantial reduction in bias relative to GEOS‐S2S‐1. The GEOS‐S2S‐2 coupled reanalysis also showed substantial improvements, attributed to the assimilation of along‐track absolute dynamic topography. The forecast skill on subseasonal scales showed a much improved prediction of the Madden‐Julian Oscillation in GEOS‐S2S‐2, and on a seasonal scale the tropical Pacific forecasts show substantial improvement in the east and comparable skill to GEOS‐S2S‐1 in the central Pacific. GEOS‐S2S‐2 anomaly correlations of both land surface temperature and precipitation were comparable to GEOS‐S2S‐1 and showed substantially reduced root‐mean‐square error of surface temperature. The remaining issues described here are being addressed in the development of GEOS‐S2S Version 3, and with that system GMAO will continue its tradition of maintaining a state‐of‐the‐art seasonal prediction system for use in evaluating the impact on seasonal and decadal forecasts of assimilating newly available satellite observations, as well as evaluating additional sources of predictability in the Earth system through the expanded coupling of the Earth system model and assimilation components.
Key Points
GMAO's New Seasonal Prediction Model and Assimilation shows substantial improvement in forecast skill over the previous version
Observed since the 1950s, the seasonal effect on underground muons is a well studied phenomenon. The interaction height of incident cosmic rays changes as the temperature of the atmosphere changes, ...which affects the production height of mesons (mostly pions and kaons). The decay of these mesons produces muons that can be detected underground. The production of muons is dominated by pion decay, and previous work did not include the effect of kaons. In this work, the methods of Barrett and MACRO are extended to include the effect of kaons. These efforts give rise to a new method to measure the atmospheric
K
/
π
ratio at energies beyond the reach of current fixed target experiments. These methods were applied to data from the MINOS far detector. A method is developed for making these measurements at other underground detectors, including OPERA, Super-K, IceCube, Baksan and the MINOS near detector.
We applied the Goddard Earth Observing System for subseasonal to seasonal climate prediction to assess the impact of inclusion biomass burning (BB) aerosols over South America (SA) during the austral ...winter. We also evaluated the model sensitivity to the BB emissions prescription using no emissions, monthly climatological, and daily emissions. Each hindcast consisted of four members running from June to November of each year between 2000 and 2015. Our results indicated that interactive BB aerosols improve the seasonal climate prediction performance over SA. More realistic daily based emissions significantly further improve the performance in comparison with the climatological ones. Therefore, improvements in the BB emissions representation are urged to represent the aerosol impacts on seasonal climate prediction performance adequately.
A primary goal of the upcoming Deep Underground Neutrino Experiment (DUNE) is to measure the (10) MeV neutrinos produced by a Galactic core-collapse supernova if one should occur during the lifetime ...of the experiment. The liquid-argon-based detectors planned for DUNE are expected to be uniquely sensitive to the νe component of the supernova flux, enabling a wide variety of physics and astrophysics measurements. A key requirement for a correct interpretation of these measurements is a good understanding of the energy-dependent total cross section σ(Eν) for charged-current νe absorption on argon. In the context of a simulated extraction of supernova νe spectral parameters from a toy analysis, we investigate the impact of σ(Eν) modeling uncertainties on DUNE's supernova neutrino physics sensitivity for the first time. We find that the currently large theoretical uncertainties on σ(Eν) must be substantially reduced before the νe flux parameters can be extracted reliably: in the absence of external constraints, a measurement of the integrated neutrino luminosity with less than 10\% bias with DUNE requires σ(Eν) to be known to about 5%. The neutrino spectral shape parameters can be known to better than 10% for a 20% uncertainty on the cross-section scale, although they will be sensitive to uncertainties on the shape of σ(Eν). A direct measurement of low-energy νe-argon scattering would be invaluable for improving the theoretical precision to the needed level.
We report new constraints on the size of large extra dimensions from data collected by the MINOS experiment between 2005 and 2012. Our analysis employs a model in which sterile neutrinos arise as ...Kaluza-Klein states in large extra dimensions and thus modify the neutrino oscillation probabilities due to mixing between active and sterile neutrino states. Using Fermilab’s Neutrinos at the Main Injector beam exposure of 10.56×1020 protons on target, we combine muon neutrino charged current and neutral current data sets from the Near and Far Detectors and observe no evidence for deviations from standard three-flavor neutrino oscillations. The ratios of reconstructed energy spectra in the two detectors constrain the size of large extra dimensions to be smaller than 0.45 μm at 90% C.L. in the limit of a vanishing lightest active neutrino mass. Stronger limits are obtained for nonvanishing masses.
To understand the principles of control and selectivity in gene expression, the biochemical mechanisms by which promoter- and enhancer-binding factors regulate transcription by RNA polymerase II were ...analyzed. A general observed repressor of transcription was purified and identified as histone H1. Since many aspects of H1 binding to naked DNA resemble its interaction with chromatin, purified H1 bound to naked DNA was used as a model for the repressed state of the DNA template. Three sequence-specific transcription factors, Sp1, GAL4-VP16, and GAGA factor, were shown to counteract H1-mediated repression (antirepression). In addition, Sp1 and GAL4-VP16, but not the GAGA factor, activated transcription in the absence of H1. Therefore, true activation and antirepression appear to be distinct activities of sequence-specific factors. Furthermore, transcription antirepression by GAL4-VP16 was sustained for several rounds of transcription. These findings, together with previous studies on H1, suggest that H1 participates in repression of the genome in the ground state and that sequence-specific transcription factors induce selected genes by a combination of true activation and release of basal repression that is mediated at least in part by H1.
We report a measurement of the atmospheric neutrino flavor ratio, R, using a sample of quasi-elastic neutrino interactions occurring in an iron medium. The flavor ratio (tracks/showers) of ...atmospheric neutrinos in a 3.9 fiducial kiloton-year exposure of Soudan 2 is 0.64±0.11(stat.)±0.06(syst.) of that expected. Important aspects of our main analysis have been checked by carrying out two independent, alternative analyses; one is based upon automated scanning, the other uses a multivariate approach for background subtraction. Similar results are found by all three approaches.
Results are reported from an improved measurement of νμ → νe transitions by the NOvA experiment. Using an exposure equivalent to 6.05 × 1020 protons on target, 33 νe candidates are observed with a ...background of 8.2 ± 0.8 (syst.). In this paper, combined with the latest NOvA νμ disappearance data and external constraints from reactor experiments on sin22θ13, the hypothesis of inverted mass hierarchy with θ23 in the lower octant is disfavored at greater than 93% C.L. for all values of δCP.
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